The use of radiant burners is common in connection with conventional cooking and heating systems. The radiating surface of the burner is typically a ceramic plate with densely spaced holes through which a combustible mixture of gas and air flows. The air/gas mixture is ignited at the ceramic surface and combustion takes place at the surface as well as partially in the holes. The velocity of the air/gas mixture through the holes is no less than the backward flame propagation velocity, so that the flame does not travel into the plenum behind the ceramic plate.
Past systems of the type disclosed, for example, in U.S. Pat. No. 6,012,444 provide a radiant burner which is approximately 28 inches by 12 inches. Such units disperse the air/gas mixture within a chamber adjacent to the ceramic plate. The air/gas mixture is dispersed by gas tubes of unequal length positioned longitudinally within the chamber, which dispersion attempts to provide equal gas distribution within the chamber and thus equal heating across and throughout the ceramic plate or plates.
It is important to assure equal heating across and throughout the surface of the ceramic plate to provide maximum and optimum radiation from all parts of the surface, and thus even cooking or heating. At the same time, the flammable gas under the ceramic plate must be the proper mixture of air and gas. For example, methane gas and air mixtures may have a variety of mixture ratios, but radiation efficiency, although difficult to measure, is believed to be optimal for complete combustion at ratios of approximately 10:1. For propane gas and air mixtures, radiation efficiency is more likely optimal for complete combustion at ratios of approximately 24:1.
A high velocity gas jet induces a sufficient quantity of air into the mixing tube or diffuser tube. The quantity of air/gas mixture needed to supply the entire radiating ceramic surface of the unit requires the mixing or diffuser tube to have a relatively large diameter.
In prior art burner units, the large mixing or diffuser tube diameter was responsible for the depth or thickness of the burner unit body behind the ceramic radiating surface, i.e. the overall thickness of the unit. Thus, such prior art burner units are generally thick or deep in the direction “d,” or the height or thickness of the burner unit. This height dimension limits use of the burner units to ovens and other applications of conventional size, which are of considerable bulk.